Pump and motor structure



m @235. s T N L N ammw PUMP AND MOTOR STRUCTURE Filed May 28, 193 2 2 Sheets-Sheet 1 A 2Q 373 27 Q 29 2,22 V/// r d De m 1935. S T, NEL ON 2,23,609

PUMP AND MOTOR STRUCTURE Filed May 28, 1932 2 Sheets-Sheet 2 Ill/IIII/II/Il/)llI/Illlllll III/Ill v 4 l I E i ,u IIIIIIIIIIIIIIIIII/IlIIIl/IIIIIIIlI/gr Patented Dec. 10, 1935 UNITED STATES PATENT OFFICE PUMP AND MOTOR STRUCTURE Sven T. Nelson, Michigan City, Ind.

Application May 28,1932, Serial No. 614,082

16 Claims.

The invention relates to pump and motor structures such as elastic fluid compressors and engines. The principal object of the invention is to provide an improved construction by which the capacity or power and the piston displacement can be greatly increased without correspondingly increasing the size and Weight or, in other words, to provide a construction in which the size and weight per unit of capacity is materially decreased as compared with compressors and engines now in use. Further objects of the invention are to provide an improved compressor or engine of large capacity or power for given size and weight and of the multiple piston radial type, that is in which the pistons and piston chambers are radially disposed about a crankshaft, and particularly to provide an improved air or gas compressor of this type.

With these and other objects in view, the invention consists in the features hereinafter set forth and more particularly pointed out in the appended claims.

In the drawings, which illustrate an air or gas compressor embodying the invention Fig. 1 is a View in vertical cross section on the line l-l of Fig. 2.

Fig. 2 is a vertical longitudinal section on the line 2--2 of Fig. 1.

Figs. 3 and 4 are detail views illustrating the piston packing.

Figs. 5 and 6 are enlarged detail views of the air inlet and outlet valves for the compressor.

In accordance with the present invention, the pistons and the cylinders, or, more properly speaking, the piston chambers, are radially disposed with reference to the crankshaft, have rectangular cross sections which are relatively long and narrow with the sectional lengths disposed parallel to or extending lengthwise of the crankshaft and the narrow sectional widths transversely thereof, and the shaft is preferably provided with multiple cranks to which each of the pistons is connected.

In the preferred construction, as shown, the casing comprises three main sections, an intermediate body section or cylinder block l and oppositely disposed heads I l abutting against the opposite end faces of the body section and suitably bolted thereto, each section being formed of a single integral casting. The intermediate body section is substantially cylindrical, is provided with a supporting base l2 and with inner partition walls forming a central crank chamber I3 and a series, five in number in the form shown, of radial piston chambers 14 which open at their inner ends into the crank chamber and extend to the end faces of the body section, being closed at their ends by the heads l i. The piston chambers thus formed by the flat partition walls l of the body section and the end heads H are materially elongated in a direction lengthwise of the shaft and contracted transversely thereof. That is to say, the piston chambers have sections in the form of long narrow rectangles, the lengths of which extend parallel to the shaft or in axial 5 direction, and the relatively narrow widths extend transversely of the shaft or in a circumferential direction. Preferably the lengths of the sections of the piston chambers are several times the widths. For example, in the form shown, the length of each piston chamber is four times that of its width.

The chambers 16 intermediate the piston chambers and bounded by the walls and circumferentially extending inner and outer walls 15 I1 and 18 form jacketing spaces which, in the form shown, are closed at their ends by the end walls 19 (see Fig. 2). Preferably also, the walls I5, I! and I8 are provided with stiffening ribs or partitions is within the chambers 16 which, to- 20 gether with the end Walls l9, aid in bracing the long flat side walls l5 of the piston chambers.

The circumferentially extending wall I 83a the outer peripheral wall 2| of the body section 10 are connected by end and intermediate partition walls 22 and 23 (see Fig. 2) and by substantially radial partition walls 24 (see Fig. 1), and these walls, in the form shown, form inlet and outlet valve chambers 25 and 26, a single inlet and a single outlet chamber being provided for each piston chamber. Preferably, the walls 24 are provided with openings 21 so that annular inlet and outlet manifolds are formed connecting the corresponding valve chambers and communicating respectively with main inlets and outlets 28 and 29 formed in the upper portion of the body section II).

The abutting faces of the body section I!) and the ends or heads ii are machined to form tight joints, and the heads are preferably provided with jacketing portions 30 and are also provided with suitable bearings 3! for the crankshaft.- The latter, in the form shown, is formed of two end sections 32 and an intermediate section 33. The end sections are provided on their inner ends with integral crank arms or checks 34 having integral crank pins 35. The intermediate section comprises crank arms 36 and an integral offset counterweighting portion 3?. The cheeks or crank arms are recessed to provide sockets 31 for receiving the inner ends of the crank pins and large bolts 38 extending through the crank arms and pins securely connect the three sections of the shaft. To prevent torsional stresses from loosening the connections between the crank pin sections, the bolts 38 extend eccentrically through the crank pins.

Each of the elongated rectangular pistons 39 is connected by two connecting rods or pitmans to the two crank pins of the shaft, all of the pitman rods associated with each pin being arranged in the same plane. One of the connecting rods 40 of each set is rigid or is formed integral with an eccentric strap or ring 4| jour- 5 naled on the crank pin between the cheeks and the other connecting rods 42 of the set have their inner ends extending within a groove in the ring 4| and pivotally connected thereto by pins 43. Lubricating ducts 44 extend through 10 the shaft sections and crank pins 35 and in line with a pipe 45 which extends between the crank arms 36 of the intermediate shaft section, and

these ducts communicate with the shaft bear-' ings 3| and with the crank pin bearings. If de- 15 sired these bearings can be readily provided with anti-friction rollers.

-- Preferably both the contacting walls of the elongated rectangular pistons and piston chambers are provided; with grooves for receiving 20- spring-pressed metal packing strips. As shown, the grooves are formed in the end and. side walls of each piston and spring-pressed straight and angular or corner packing strips 46 and 4'! are arranged therein, and are provided with over- 25' lapping ends as indicated in Figs. 3 and 4. These packing strips and grooves are arranged near the outer end of the pistons and at their inner ends the flat side walls l5 of the piston chambers and the end walls thereof formed by the 30 heads II are provided with grooves for receiving spring-pressed metal packing strips 48 and 49. Preferably, for convenience in manufacture the packing strips 49 and the grooves formed in the heads II are circular and each of the pack- 35 mg strips 48 is formed of, two sections having l" overlapping ends and pressed apart in longitudinal direction by a spring 50, as shown in Fig. 2. fly woviding both pistons and the walls of the piston chambers with packing strips, tight joints 4 are assured. Each piston comprises an outer end wall or head of elongated rectangular form, and a skirt comprising side and end walls 52 and 53, an intermediate stiffening wall 54 parallel with 45 the side walls 52 and a transverse stiffening partition 55. The intermediate partition is provided with enlarged portions 56 for receiving the pitmans 40 and 42, and this stiffening partition 50 54 and the stiffening partition 55 are cut away to receive and permit the relative movement of the pitmans.

The construction is of adequate strength and tight joints can be formed between the pistons 55 and walls of the piston chambers, notwithstanding their elongated rectangular section. Also, the series of radial rectangular pistons and piston chambers provides a structure in which the size and weight per unit of capacity or power 0 is very materially decreased, or in other words,

for a given size and weight, the capacity or piston displacement is very materially increased. Thus it is estimated that the particular structure shown need not be materially greater in size 65 andweight than a five cylinder radial compressor or engine, but would have .nearly four times the piston displacement; Furthermore, either for a compressor or an engine the valve arrangement would be materially simplified for the same ca- 70 pacity.

In the construction illustrated, compressor inlet and outlet valves are shown and are carried by suitable valve seats mounted on the flattened portion of the partition wall 18 at the outer 75 ends of the piston chambers, sufficient space bepin 51 by which the piston is connected to the ing provided for a large inlet and a large outlet valve for each piston chamber. The inlet valve seat 58 is circular in section and rests upon a circular shoulder or rabbet 59 formed in the wall l8. A thin metal valve disk 60 held in place 5 by a spring disk 6! normally closes the ports 62 in the valve seat, these parts being guided on a hub portion 63 of the valve seat. A bolt 64 having a nut 65 on its outer end, threaded centrally through the valve seat, holds a resilient abutment consisting of a plate 66 and washers 67 in position and which cushion the opening movement of the inlet valve. A bolt 68 threaded into the outer wall 2| of the main body of the casing engages the outer end of the bolt 54 and removably holds the valve seat and valve in position.

The outlet valve is of somewhat similar construction. It comprises a valve seat 69 seated in a rabbet 1E! and similar valves, valve springs and cushioning abutment .plate and washers, these parts being mounted on the hub portion H of the valve seat and held in place by nuts 12 threaded on the hub. A bolt 13 having a head 14 thereon is threaded'through the hub of the valve seat and engages an offset on the casing wall 2| and removably holds the outlet valve and valve seat in position.

The outer end walls of the valve chambers and r corresponding portions of the heads I I of the casing are provided with openings of sufiicient size to permit the insertion and removal of the valves and these openings are normally closed by removable cover plates 15. It is also noted that the ends or heads H are provided with openings 16 extending therethrough which open into the crank chamber and these openings are normally closed by cover plates 11. Suitable inlet and outlet ports, not shown, may be provided for circulating medium through the jacketing spaces I6 and 30.

The body section H! is provided at the lower portion of the crank chamber l3 with a troughlike portion 19 for the collection of lubricant. The portions of the end faces of the body section between the piston chambers are grooved, as at 80, so that the spring-pressed packing strips or rings 49' can snugly engage the narrow end walls 53 of the pistons.

While the particular construction shown is adapted and intended as an air or gas compressor, it is obvious that suitable valves and ignition mechanism could be provided to adapt the construction for use as an internal combustion engine which is either air or water cooled. If air cooled, the spaces between the radial cylinders could be left open for circulation of air therethrough. Other changes may be made in the details set forth without departure from the scope of the invention as defined in the claims. 80

I claim as my invention:

1. In an elastic fluid pump or motor structure,

a frame or casing having a crank chamber, a crankshaft extending therethrough, the casing having a series of relatively fixed radial piston chambers of elongated, substantially rectangular section with their relatively long side walls extending lengthwise of said shaft, an inlet and an outlet valve at the outer end of each of said chambers, pistons in said chambers and connect- 70 ing rods coupling the piston to a common crank or cranks of said shaft.

2. An elastic fluid pump or motor structure comprising a frame or casing, a crankshaft journaled therein, the casing having a relatively fixed 76 piston chamber of elongated, substantially rectangular section extending lengthwise of the shaft, a piston fitting the chamber and two or more spaced pitman rods directly connected to the piston and the crankshaft.

3. In a pump or motor structure, a casing comprising oppositely disposed heads and an intermediate body section, the latter having walls extending between said heads and forming the relatively long side walls of rectangular piston chambers, the narrow side walls of which are formed by said heads, a crankshaft journaled in said heads, and pistons in said chambers connected to said shaft.

4. In a pump or motor structure, a shaft having two or more cranks, a plurality of piston chambers rectangular in section disposed in a circular series about the shaft with the relatively long side walls thereof extending lengthwise of the shaft, and pistons in said chambers, each connected to the multiple cranks of said shaft.

5. In a pump or motor structure, a casing comprising oppositely disposed heads and an intermediate substantially cylindrical body section, the latter having a circular series of rectangular piston chambers and intermediate jacketing spaces formed therein, the chambers being closed at their ends by said heads, a crankshaft journaled in said heads, pistons in said chambers, and a plurality of spaced pitman rods connecting each piston to said shaft.

6. In a pump or motor structure, a casing comprising a substantially cylindrical body, having formed therein a circular series of radial piston chambers of rectangular section open at the ends of the cylindrical body and intermediate jaoketing spaces closed at their ends, heads secured to the opposite ends of said body and forming the ends of said piston chambers, a crankshaft journaled in said heads, and pistons in said chambers connected to said crankshaft.

'7. In a structure of the class described, 2. casing comprising oppositely disposed heads and an intermediate body, the latter having a central crank chamber, a circular series of radial rectangular piston chambers closed at their relatively narrow ends by said heads, intermediate jacketing spaces and annular inlet and outlet manifolds, a crankshaft journaled in said heads and extending through said crank chamber, pistons in said piston chambers, and a pair of spaced pitman rods connecting each piston to said shaft.

8. In a compressor or engine structure, a series of radial pistons and piston chambers of enlarged rectangular section, a shaft having multiple cranks to which each of said pistons is connected, said shaft comprising multiple sections providing crank arms and pins and bolts extending through the crank pins and arms and rigidly connecting the shaft sections.

9. In a compressor or engine structure a series of radial pistons and piston chambers of enlarged rectangular section, a shaft having multiple cranks to which each of said pistons is connected, said shaft comprising multiple sections having integral crank arms, crank pins integral with certain of said arms and seated in recesses in the adjacent arms, and bolts extending through the crank arms and eccentrically through the crank pins for rigidly connecting said sections.

10. In a compressor or engine structure, a crankshaft, a series of radial pistons and piston chambers of elongated rectangular section disposed about and lengthwise of the shaft, with each piston connected to a common crank or cranks thereof, and packing strips on the outer portions of the pistons and on the inner portions of the 5 walls of the piston chambers.

11. In a structure of the class described, a casing comprising oppositely disposed heads and .an intermediate body, the latter having a central crank chamber and a circular series of radial rectangular piston chambers closed at their relatively narrow ends by said heads, and annular inlet and outlet manifolds, removable inlet and outlet valves and valve seats disposed in said manifolds at the outer ends of said piston chambers, a crankshaft journaled in said heads and rectangular pistons in said chambers connected to the crankshaft.

12. In an elastic fluid pump or motor structure, rotor and stator members, one comprising a crankshaft having aligned crank arms and the other a frame or casing having a crank chamber through which said crank extends and a. plurality of piston chambers, said chambers in cross section being elongated lengthwise of the shaft and substantially contracted transversely thereof, correspondingly shaped pistons in said chambers, and two spaced pitman rods connecting each piston to the aligned crank arms of said shaft.

13. In an elastic fluid pump or motor structure, rotor and stator members, one comprising a crankshaft and the other a plurality of radial piston chambers having cross sections substantially elongated lengthwise of the shaft and contracted transversely thereof, correspondingly shaped pistons in said chambers, and two spaced pitma rods directly connected to each piston and th crankshaft. o

14. In a structure of the class described, a casing comprising oppositely disposed heads and an 40 intermediate body, the latter having a central crank chamber and a circular series of radial, substantially rectangular piston chambers closed at their relatively narrow ends by said heads, a crankshaft journaled in said heads and extending through the crank chamber, pistons fitting the piston chambers and connected to the crankshaft, and packing strips in the relatively long side walls of the piston chambers and in said heads and engaging the pistons.

15. An elastic fluid pump or motor structure comprising a casing, a crankshaft, the casing having a crank chamber and a radial series of piston chambers of substantially rectangular section elongated lengthwise of the shaft, corresponding- 50 ly shaped pistons in said chambers, and two or more pitman rods connected directly to each piston and to the shaft, the rods being arranged in twoor more sets and those of each set disposed substantially in a common plane. 6

16. An elastic fluid pump or motor structure comprising a casing, a crankshaft journaled therein, the casing having a crank chamber and a circular series of radial piston chambers substantially rectangular in section and elongated 5 lengthwise of the shaft, inlet and outlet manifolds, inlet and outlet Valves connecting the manifolds with the outer end of each piston chamber, pistons in the chambers and a pair of spaced pitman rods connecting each piston with the crankshaft.

SVEN T. NELSON. 

